The present invention generally relates to communication connections. More particularly, it relates to an apparatus and method for retaining a connection between male and female connectors, such as USB connectors, to minimize the occurrence of accidental disconnects between the connectors.
Connections using the Universal Serial Bus (USB) standard are becoming increasingly more commonplace and useful in computer peripheral devices, audiovisual equipment, and electronic devices in general. Such devices have advantages including a simple mechanical connection, an ability to connect and disconnect while a device is in operation (xe2x80x9chot pluggingxe2x80x9d), an ability to connect several devices, and a large selection of devices using this connection standard.
FIG. 1 shows typical prior art male 10 and female 12 A-side USB connectors, also known as A-type or Series A connectors. The principal mechanical and electrical characteristics of these connectors are standardized according to convention known in the art. The female connector 12 or socket contains a metal connector casing 14 having upper 16 and lower 18 surfaces, each surface having a pair of retention prongs 20 typically cut and formed out of the resilient metal used to manufacture the metal connector casing. The retention prongs 20 each have a detent 22 for holding the male connector 10, created by bending a portion of the retention prongs inwardly (for the upper surface 16 as shown, downwardly, and for the lower surface 18, upwardly).
The male connector 10 has a metal connector body 24 connected to a cable 26 for communication with a device. The connector body 24 contains upper 28 and lower 30 surfaces, each having a pair of receiving portions, such as typically square surface holes 32, which are aligned with the detents 22 of the retention prongs 20 of the female connector 12 when the male connector 10 is fully inserted. As shown in FIGS. 2A-2C, as the male connector 10 is inserted into the female connector 12 (FIG. 2A), the upper and lower retention prongs 20 are forced outwardly from an inner resting position to an outwardly flexed position (FIG. 2B). When the male connector 10 is inserted to the point where the retention prongs 20 align with the surface holes 32 (FIG. 2C), the retention prongs, being made of resilient material, naturally return inwardly toward an inner holding position and the detents 22 partially fall into the surface holes 32, creating a snap fit which retains the connection. Because the detents 22 of the retention prongs 20 are somewhat rounded, this type of connection allows relatively easy insertion and removal (see FIGS. 2D and 2E) of the male connector 10 from the female connector 12, while providing a degree of resistance to disconnection.
FIG. 13 shows a typical prior art B-side male connector 80 and a female (socket) connector 88. The male connector 80 includes a cable 26 and a metal connector body 82 having a pair of side surfaces 84, only one of which is visible in FIG. 13. Each of the side surfaces 84 includes a vertically extending outward projection 86 having a rounded surface. When the male connector 80 is inserted into the female connector 88, inwardly extending ends of a pair of rotation prongs 92 on side surfaces 90 (only one side surface is visible in FIG. 13) of the female connector engage receiving portions of the male connector on a rearwardly facing side (in FIG. 13, the left side) of the projections 86.
The connection is thus retained, but the male connector 80 and female connector 88, like the A-side male 10 and female 12 connectors, can be easily connected and disconnected due at least in part to the rounded surface of the projections 86.
However, such ease of connection and disconnection creates a problem for use in devices where a more secure attachment is desired. For certain electrical devices, it is desirable to connect products easily, yet keep them from inadvertently disconnecting. In such devices, a user may need to connect the device only once, and not disconnect the device unless the device needs to be moved. For these devices a user may not desire such easy disconnection. Or, the user may wish to have a connection that provides easy insertion and de-insertion, while also providing a lock to prevent accidental disconnection. Certain environments may include positioning of the connected device that creates tension on the USB cable. If the device is moved or jostled, even unintentionally, the cable is prone to undesirably disconnect from the device.
Prior solutions to this problem, such as clamps, mounting clips or other methods of strain relief have proved ineffective to solve the problem of providing a USB connection that, while easy to connect, is not too easily disconnected.
The present invention provides an inventive apparatus and method for retaining the connection of first and second electrical connectors, while still allowing a relatively easy connection. The basic concept of this invention is to increase a required connector extraction force or lock the connection so the device is not inadvertently disconnected. The present invention retains the connection by, among other things, modifying a device containing a second connector to create a restraining element for biasing the retention prongs toward an inner holding position, or by modifying the retention prongs of the second connector.
In one embodiment, a device having a second connector is modified to form a restraining element for providing pressure to the retention prongs, to bias them towards an inner holding position. This restraining element may include one or more cutouts forming flexible members in a connection area of the device surrounding the second connector, and may have one or more pairs of contact members supported by the flexible members for contacting the retention prongs.
In another embodiment, a restraining element in the form of a sliding latch may be used in which the sliding latch contains a pair of elongated legs having teeth and slots. The sliding latch may be slidingly positioned so that either the teeth or the slots are aligned with the retention prongs. When the teeth are aligned with the retention prongs, they substantially prevent the retention prongs from moving to an outwardly flexed, non-holding position, thus locking a connection. In a related embodiment, a second connector can be fitted with a sleeve having inwardly projecting stops which can be positioned toward the retention prongs, to maintain the retention prongs in their holding position.
In yet another embodiment, the retention prongs of the second connector are modified by forming at least one barbed projection which is acutely angled towards the back of the second connector. The barbed projection enters the surface holes of the first connector as it is inserted and substantially prevents removal of the first connector unless the modified retention prongs are separately lifted by, for example, manipulating a tab connected to the modified retention prongs.